Ice cube tray



J. A. GITS ICB CUB! TRAY Filed Sept. 5, 194?? Dec. Z3, 1947 Y r2Sheets-Sheet 1 JNVENTo Josep/L- a. Giw

Dec. 23, 1947. J. A. Grrs 2,433,211

ICB CUBE mY Filed Sept. 5, 1947 '2 Sheets-Sheet 2 lo fblg /l wwwPatented Dec. 23, 1947 UNITED STATES PATENT oFFicE ICE CUBE TRAY JosephA. Gits, Chicago, lll., assis-no1' of one-half to Jules P. Gib, Chicago,Ill.

Application september s, 1947, serrer no. 112,390 z chime. (ci. sz-ioasThis application is a continuation in part of applications Serial No.418,753, `filed November -12, 1941, and Serial No. 575,798, filedFebruary 2, 1945. Y

This invention relates to freezing trays and more particularly tofreezing trays for forming ice -cubes and the like.

The difrculties of removing ice cubes from freezing trays are generallywell known. Freezing trays most widely sold have been made of metal andrubber. Neither has served the purpose satisfactorily. Metal trays werefirst provided with the common dividers which required the messy task ofrunning water over the trays and the dividers to partially melt thecubes before they could be removed A substantial portion of the cubesmelted and the entire tray had to be refrozen each time, even thoughonly one or two cubes were desired. The next step in the metal traydevelopment was the use of levers tending to jar the dividers to releasethe cubes without the use of water. These levers are not entirelysatisfactory beca'use they tend vto break at ltheir connection with thedividers.

They also tend to shatter the ice cubes if the latter have been frozenat low temperatures, so that it becomes impossible to remove wholecubes. Again, all the cubes are disturbed and it is impossible to usefew cubes and refill the tray without completely emptying the tray, thuswasting the unused cubes.

Rubber trays have been less valuable and have become practically extinctas the result of unsatisfactory use over a period of several years.Rubber trays will not readily free the cubes. Each cube must be peeledou The tedious task involved has also resulted frequently in the use ofwarm water over the tray to melt the cubes in the same manner as themetal trays.

There have been attempts in the case of both metal and rubber trays tocoat the surfaces-of the compartments in an effort to minimize the bondbetween the ice and the walls of the trays. These coatings will inpractice last for a short time and will disappear after some twenty tothirty freezings of the tray. Hence, these coatings are effective onlywhile the trays are new.

Both the metal and rubber trays tend to freeze to the walls of therefrigerator chest and accumulate frost thereabout so that either therefrigeration unit must be defrosted to remove the trays, orconsiderable tugging and chopping are necessary to loosen the trays. Inthe trays of the prior art, no regard has been given in the constructionto the expansion of the ice upon 2 freezing increasing the bond holdingvthe cubes tightly in the cube compartments, and hence. no effort hasbeen made to utilize the expansion as a. means to eject the cubes, say,when the contact between the ice cubes and the tray walls is disturbed.

An object of the invention is to provide a new and improved type of icecube tray having walls of a tough resilient material with a wax-likesur-- face which, when bowed, will have a. retractile force capable ofejecting the ice cubes from the compartment when the contact between theice cubes and the tray walls is disturbed.

The present invention is based upon the discovery that the expansion ofthe ice upon freezing may be utilized in a tapered wall preferably toeffect a quick release of the cubes by causing this expansion of the iceto bow the wall or at least place it under such tension or resiliencythat the resultant retractile force will eject the cubes when thecontact between the ice cubes and the tray walls is disturbedsufficiently to allow the bowed walls to return to their originalposition. l

i A further object of the invention is toprovide a new and improved typeof ice cube tray and to use in this tray a material known specificallyas polyethylene.

A still further object of the invention is to provide a new and improvedtype of ice cube tray made `of polyethylene or equivalent material whichwill overcome the defects of the prior art structures, to-wt; which willprovide for'quick release of the ice cubes without the use of mechanicalaids or require the running of water on the tray to melt the ice cubesin order to free them, which will provide for removal of one or morecubes without requiring the waste of the remaining cubes uponrefreezing, and which will provide for easy removal of the tray itselffrom the refrigerator chest without requiring defrost-V ing of therefrigeration unit or the tugging or chopping at the tray to free thesame. l

A still further object of the invention is to a provide a freezing traywhich will eject the cubes by actually popping the same out of the traycompartments by a mere twist after the tray is gripped at the ends.

A still further object of the invention is vto provide an improvedfreezing tray which will remain stable at temperatures as low as minus50 Fahrenheit, and which will be non-toxic, odorless and sanitary, and`capable of relatively rough usage for a long period of time.

Other objects and advantages of the invention will be apparent from thefollowing detail description when taken in connection with theaccompanying drawings forming a part thereof, in which: v

Figure 1 is a view illustrating the way the ice cubes are ejected fromthe freezing compartments when the tray is twisted at the ends torelease the contact between the cubes and the bowed walls of thecompartments, so that these bowed walls will by their contractile actionpop the cubes upwardly out of the compartment;

Fig. 2 is a view in perspective of the tray;

Fig. 3 is a top plan view oi the tray to illustrate how the freezingcompartments are distorted to permit the bowed walls thereof to releasetheir contact with the ice cubes;

Fig. 4 is an enlarged view in section of several freezing compartmentsto illustrate how the expansion of the ice cubes during freezing causesthe side walls of the freezing compartments to -bow slightly;

Fig. 5 is a view of these same compartments after the ice cubes areremoved to illustrate how the bowed walls return to normal position;

Fig. 6 is an ice cube frozen in a compartment of the freezing traydisclosed herein;

Fig. 7 illustrates an ice cube frozen in a metal tray;

Fig, 8 is a longitudinal section of the tray;

Fig. 9 is a bottom view of the same; and

Fig. 10 is a transverse section of the tray taken on line Ill-I0 of Fig.9.

For the purposes of illustration, I have shown one form of theinvention. It is to be understood that this structure merely illustratesthe invention disclosed so that those skilled in the art will be readilytaught how to practice the invention.

The ice cube or freezing tray I comprises a plurality of individualcompartments 2, and while they may be arranged in any desirable design,I have shown an appealing arrangement of two rows wherein thesecompartments are somewhat rectangular but in proper balance to produce apleasing appearance. Each compartment 2 is defined by four side walls,3, 4, 5, and 6, and a bottom wall l. The inner end side walls may bedesignated 4 and the outer end sidewalls may be designated 3.

The upper portion of the side walls 3 to 6, inclusive, merge into whatmay be called an upper ledge I0 that extends about all sides of the trayas well as between the rows longitudinally of the tray and crosswise ofthe tray between adjacent compartments 2 of each row. These side Wallssection at the bottom. Exteriorly of compartments 2, air spaces IIextend crosswise of the tray between adjacent compartments of each rowand an air space I2 extends longitudinally of the tray between the tworows.

Fig. 1 illustrates how the tray I may be given a torsional twist, thatis, twisted by gripping the ends and rotated in opposite directions. Byemploying the structure disclosed herein, the contact between the icecubes and the walls 3, 4, 5, and 6 is disturbed and the ice cubes I'Iare forced out by a popping-like action. To limit the twisting actionand to aid in transmitting the torsional twist, ribs I3 and I4 or theirequivalent may be provided to connect adjoining compartments at thebottom. It will be apparent that the tray I will not suifer abusereadily from excessive twists that permanently distort the tray and willnot be torn if handled improperly. These ribs I3 and moplastic, but I 4Il also transmit the twist and cause the walls of the respectivecompartments to more readily flex.

To carry out the invention, the walls of the compartments are made of amaterial preferably having a wax-like surface and of high tensilestrength, yet yieldable to the expansion of the ice cubes I'I whenfreezing so that the walls 3, I, 5, and 6 will be bowed as illustratedat i5 in Fig. 4, the cubes being held in the compartments 2 until thecontact between these walls and the ice cubes is disturbed when theretractile force of the walls returning to their normal position ejectsor pops the cubes upwardly out of the compartments. This material isknown as polyethylene, which is a polymerization of ethylene at hightemperatures.

The purpose of the invention is to provide a tray with walls 3, 4, 5, 6,and 'I suiiiciently rigid so that they will not have a limp, rubberyaction. These walls possess an urge to return to their original positionwhen the force holding them under tension or bowed is released. Theyshould also yield to a force pressing against them so that this forcemay increase without fracturing or cracking the walls. By having thewalls bowed by this force, the ice cubes I1 may expand upon freezing andalso continue with further expansion if subjected to lower temperaturesas in a quick freeze refrigeration unit without rupturing the wall. Thebowing very aptly aids in popping the cubes out of the compartments.

Ice cubes I 'I will have convex faces as indicated at I 6 in Fig. 6,which will cause the walls 3, 4, 5, and 6 and also the bottom I to yieldand thus be bowed as indicated at I5 in Fig. 4. By having walls 3, 4, 5,and 6 promptly responding to any disturbance, the ice cubes are causedto be popped or ejected forcibly out of the compartments 2. These walls,when thus responding to such disturbance, will be restored instantly totheir normal condition, and the ice cubes then being of larger crosssection due to the convex Walls I6 Will not return into thecompartments. The walls are of such character that the retractile forcerestoring them to original position will continue to hold them in theiroriginal position and prevent the ice cubes from being physically pushedback into The frictional resistance between the walls of thecompartments and the ice cubes should be less than the force restoringthe walls to their normal position. Polyethylene has a wax-like surfaceand is not wettable by water. Ice will not adhere thereto. Consequently,the retractile force tending to return the bowed walls 3, 4, 5. 6, and'I to normal position should not be too great. Polyethylene isclassified as a rigid therfind that if the walls 3 to 'l inclusive aremade of a thickness ranging from .025 to .110 of an inch, the materialwill have a toughness and flexibility that will possess a retractileforce returning the bowed walls to normal position only after thecontact between the ice cubes and the walls has been disturbed asillustrated in Fig. 1. This retractile force will not disturb the icecubes during freezing. The expansion of the ice cubes will, on the otherhand, bow the walls and keep them bowed until their contact with the icecubes is disturbed.

With the walls 3, 4, 5, and 6 being tapered, compartments 2 are largercross sectionally at the top than at the bottom. Consequently, when thetray I is twisted rotationally in oppositedirections, all the wallsincluding the bottom are position in the compartments..

polyethylene is has low moisture absorption. It is extremely stabledistorted. The shapes assumed by the compartments and their walls willbe seen in F18. 3. while Fig. 2 illustrates but flexible walls will bedistorted into a spiral formation. Thus the walls are no longer planarbut will be restored instantly upon being released.

Aside from providing the desired retractile force accomplishing thepurposes of the invention when the walls have a proper thickness.non-toxic, chemically inert and and retains its flexibility and tensilestrength at low temperatures. While polyethylene may have a plasticizeradded thereto, this is not necessary, and consequently, it will remainstable at very low temperatures and will not crack, fracture, orshatter. v

Another advantage obtainable from tray i is that any number of ice cubesmay be removed without disturbing the others. By confining the twistingaction to one or two compartments, it

is possible to eject the cubes of such compartments without disturbingthe cubes in the remaining compartments. Moreover, the tray will notfreeze to the walls of the refrigeration chest, nor will any substantialamount of frost accumulate about the tray, so that it is not necessaryto chop or tug at the tray to remove it from the chest, nor is itnecessary to defrost the refrigerating unit.

It-is found that a wall thickness of from .045 to .075 of an inch isparticularly suitable in the tray disclosed herein, lthough, as stated,a thickness from .025 to .110 of an inch will work. Unless the wallthickness varies, the bowing due to the expansion of the ice cubes uponfreezing will be uniform or substantially so in all walls. If the wallsshould vary in thickness, the bowing will be greater in the walls ofless thickness and the ejection of the ice cubes from the compartthetray in normal position. When the tray is twisted, the semi-rigid' ments2 may not occur with the same force as when all the side walls areevenly bowed.

The polyethylene ice cube tray disclosed herein overcomes all thedifnculties experienced in removing ice cubes from freezing trays of theprior art. Polyethylene is tough and will not be affected by age to anyappreciable extent. It is unlike other thermoplastics in that it willnot crack or fracture by the freezing of water which may overow from acompartment being refilled into an adjacent compartment having g, looseice cube therein. This overflow. when freezing be tween the loose cubeand the walls of its compartment, will in other thermoplastics splitthese walls.

While the invention is particularly directed to freezing trays forfreezing ice cubes, it may be adapted to freezing trays for frozencakes, etc., when substantially the same problems of removal may beinvolved. Tray I is preferably produced by iniection molding, but it mayalso be formed out of sheet material.

Without further elaboration, the foregoing will so fully explain thegist of my invention that others may, by applying current knowledge,readily adapt the same for use under varying conditions of service,without eliminating certain fea- Atures, which may properly be said toconstitute `l0 the essential items of novelty involved, which items areintended to be defined and secured to me by the following claims.

I claim:

. l. An ice freezing tray comprising a body formed of individualcompartments, each having tapered side walls integrally formed with eachother andwith a bottom wall, the side walls of adjoining compartmentsbeing joined together along their top edges, all said walls being formedof polyethylene having wax-like surfaces substantially non-wettable bywater and to which ice will not adhere, said material yielding undertension to the expansion of the ice upon freezing in each compartment,said tapered walls being of a thickness ranging from .025 to .110 of aninch and being bowed outwardly by such expansion, said polyethylene wallstructure due to said thickness producing a retractileforce sufilcientto return the bowed walls to normal condition and to eject the cubesfrom said when the bowed walls are disturbed by manual flexing.

2. A freezing tray composed of a plurality of freezing cells integrallyunited at their top portions and forming a continuous integral cell-likebody, each cell having a bottom wall and tapered side walls formed ofpolyethylene yielding to and bowed by the expansion of theice uponfreezing, said walls being of a thickness ranging from .025 to .110 ofan inch and capable of producing a retractile force electing the icefrom said cells when the bowed walls are flexed and restored to normalcondition.

JOSEPH A. GITS.

assumons crrzp The following references are of record in th ille of thispatent:

OTHER REFERENCES Article "Polyethylene," in Plastics, Sept. 1944, pages39 to 43 and 11 relied on.

compartments

